<template>
  <div class="drag" ref="dragDiv">
    <div class="drag_bg"></div>
    <div class="drag_text">{{ confirmWords }}</div>
    <div
      ref="moveDiv"
      @mousedown="mousedownFn($event)"
      :class="{ handler_ok_bg: confirmSuccess }"
      class="handler handler_bg"
      style="position: absolute; top: 0px; left: 0px"
    ></div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      beginClientX: 0,
      /* 距离屏幕左端距离 */
      mouseMoveStata: false,
      /* 触发拖动状态  判断 */
      maxwidth: "",
      /* 拖动最大宽度，依据滑块宽度算出来的 */
      confirmWords: "拖动滑块验证",
      /* 滑块文字 */
      confirmSuccess: false /* 验证成功判断 */,
    };
  },
  methods: {
    mousedownFn: function (e) {
      if (!this.confirmSuccess) {
        e.preventDefault && e.preventDefault(); // 阻止文字选中等 浏览器默认事件
        this.mouseMoveStata = true;
        this.beginClientX = e.clientX;
      }
    }, // mousedoen 事件
    successFunction() {
      this.confirmSuccess = true;
      this.confirmWords = "验证通过";
      if (window.addEventListener) {
        document
          .getElementsByTagName("html")[0]
          .removeEventListener("mousemove", this.mouseMoveFn);
        document
          .getElementsByTagName("html")[0]
          .removeEventListener("mouseup", this.moseUpFn);
      } else {
        document
          .getElementsByTagName("html")[0]
          .removeEventListener("mouseup", () => {});
      }
      document.getElementsByClassName("drag_text")[0].style.color = "#fff";
      document.getElementsByClassName("handler")[0].style.left =
        this.maxwidth + "px";
      document.getElementsByClassName("drag_bg")[0].style.width =
        this.maxwidth + "px";
    }, // 验证成功函数
    mouseMoveFn(e) {
      if (this.mouseMoveStata) {
        let width = e.clientX - this.beginClientX;
        if (width > 0 && width <= this.maxwidth) {
          document.getElementsByClassName("handler")[0].style.left =
            width + "px";
          document.getElementsByClassName("drag_bg")[0].style.width =
            width + "px";
        } else if (width > this.maxwidth) {
          this.successFunction();
        }
      }
    }, // mousemove事件
    moseUpFn(e) {
      this.mouseMoveStata = false;
      var width = e.clientX - this.beginClientX;
      if (width < this.maxwidth) {
        document.getElementsByClassName("handler")[0].style.left = 0 + "px";
        document.getElementsByClassName("drag_bg")[0].style.width = 0 + "px";
      }
    }, // mouseup事件
  },
  mounted() {
    this.maxwidth =
      this.$refs.dragDiv.clientWidth - this.$refs.moveDiv.clientWidth;
    document
      .getElementsByTagName("html")[0]
      .addEventListener("mousemove", this.mouseMoveFn);
    document
      .getElementsByTagName("html")[0]
      .addEventListener("mouseup", this.moseUpFn);
  },
};
</script>

<style scoped>
.drag {
  position: relative;
  background-color: #e8e8e8;
  width: 30%;
  height: 34px;
  line-height: 34px;
  text-align: center;
}

.handler {
  width: 40px;
  height: 32px;
  border: 1px solid #ccc;
  cursor: move;
}

.handler_bg {
  background: #fff
    url("")
    no-repeat center;
}

.handler_ok_bg {
  background: #fff
    url("")
    no-repeat center;
}

.drag_bg {
  background-color: #7ac23c;
  height: 34px;
  width: 0px;
}

.drag_text {
  position: absolute;
  top: 0px;
  width: 100%;
  text-align: center;
  -moz-user-select: none;
  -webkit-user-select: none;
  user-select: none;
  -o-user-select: none;
  -ms-user-select: none;
}
</style>
